math

classic Classic list List threaded Threaded
2 messages Options
lula lula
Reply | Threaded
Open this post in threaded view
|

math

a rectangular auditorium seats 1170 people.  The number of seats in each row exceeds the number of rows by 19  Find the number of seats in each row.
McGenius McGenius
Reply | Threaded
Open this post in threaded view
|

Re: math

r = number of rows
r + 19 = number of seats in each row

r(r + 19) = 1170   ← total seats equals number of rows times number of seats in each row
r² + 19r = 1170   ← distributive
r² + 19r - 1170 = 0   ← subtracted 1170
(r + 45)(r - 26) = 0   ← factored
r + 45 = 0   or   r - 26 = 0   ← set to zero
r = -45   or   r = 26   ← solved

r + 19   ← number of seats in each row
= 26 + 19   ← substituted
= 45   ← added

45 seats in each row

*McGenius*